According to Chin's former owners, he was found by some people who decided to simply give him away. But that scenario is "highly unlikely," Tom Taylor, assistant director at Wildlife Friends Foundation Thailand (WFFT), told The Dodo.

Regardless of where he came from, Chin was more than likely taken from his mother in the wild - mother animals are often killed so their babies can be sold in the pet trade - and then began his life as someone's pet. He probably would have spent his life there but, unsurprisingly, his health started to deteriorate, WFFT wrote on Facebook.

"The current owners had kept him for four months," WFFT wrote. "During this time, his ability to move around and climb gradually became worse."

At a loss about what to do with Chin, his owners brought him to WFFT, where he underwent a physical examination that revealed his sad secret: Chin was suffering from metabolic bone disease. The illness deforms an animal's bones, making it hard for them to move or even eat normally.

Luckily, the disease is treatable. With a proper diet consisting of fruits, insects and vitamin supplements, in addition to physiotherapy and time spent outdoors where he can soak up the sun, WFFT hopes Chin's condition will improve.